OFFSET
1,2
COMMENTS
Each member of the sequence is either 4*a+b for a in the sequence and b in {1,2,3}, or 4*a for a in A023705. - Robert Israel, Oct 04 2018
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
R23705:= {1, 2, 3}:
R:= {}: A:= 0;
for i from 1 to 4 do
R:= map(t ->4*t, R23705) union map(t -> (4*t+1, 4*t+2, 4*t+3), R);
R23705:= map(t -> (4*t+1, 4*t+2, 4*t+3), R23705);
A:= A, op(sort(convert(R, list)));
od:
A; # Robert Israel, Oct 04 2018
MATHEMATICA
Select[ Range[ 0, 160 ], (Count[ IntegerDigits[ #, 4 ], 0 ]==1)& ]
PROG
(PARI) isok(n) = (n==0) || (#select(x->(x==0), digits(n, 4)) == 1); \\ Michel Marcus, Oct 04 2018
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved